S1016
Clinical – Paediatric tumours
ESTRO 2026
1 Pôle de Pneumologie, ORL (airways) & Dermatologie (skin), Groupe Recherche en Kinésithérapie Respiratoire, Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium. 2 Service de kinésithérapie et ergothérapie, Cliniques universitaires Saint-Luc, Brussels, Belgium. 3 Molecular Imaging-Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium. 4 Service de Radiothérapie Oncologique, Cliniques universitaires Saint-Luc, Brussels, Belgium Purpose/Objective: Respiratory motion is a major challenge in paediatric thoracic radiotherapy, where minimizing exposure to healthy tissues is essential to reduce long-term toxicity and improve quality of life in long-term survivors[1]. Mechanically-assisted non-invasive ventilation deep inspiration breath-hold (MANIV-DIBH) enables non- sedated patients to achieve repeated, reproducible breath-holds, potentially reducing safety margins and improving dose conformity[2-3]. We report the first paediatric application of MANIV-DIBH during whole lung irradiation. Material/Methods: A 10-year-old girl with metastatic Ewing sarcoma underwent whole lung irradiation following chemotherapy and surgery. First, a preparatory session with a physiotherapist introduced MANIV- DIBH using child-friendly communication, during which he also selected the optimal non-vented oronasal mask. Then, a simulation session was performed to define ventilator settings for assisted breath-holds using APRV mode, adjusted to the child’s tolerance. A CT scan acquired during breath-hold was used for treatment planning and margin definition. The target was to achieve multiple 20-second breath- holds. Treatment was subsequently delivered with IMRT, applying MANIV with identical parameters during the several treatment fractions. Results:
treatment sessions, with an average treatment time per fraction of 32.1 (±7.8) minutes. Simulation confirmed anatomical stability, enabling planning margins of 5–7 mm. Most dose constraints were met: D95PTV = 96.7%, mean heart dose = 11.22 Gy (influenced by a left scapular titanium prosthesis). Only grade 2 fatigue occurred. Follow-up PET/CT showed complete response and no radiological toxicity.
Conclusion: This first use of MANIV-DIBH in paediatric thoracic radiotherapy demonstrates feasibility and good tolerability in children. The technique improved geometric separation between target and OARs, allowing reduced margins and better sparing of organs at risk. Collaboration between physiotherapists and radiotherapy teams was essential for patient preparation. While challenges remain—such as paediatric-specific interfaces and tailored communication—this proof-of-concept supports further clinical evaluation, particularly in proton therapy where reproducibility is critical. MANIV-DIBH may represent a safe, effective strategy to reduce radiation-induced toxicity and improve long-term outcomes in children. References: 1. Constine, L.S., et al., A User's Guide and Summary of Pediatric Normal Tissue Effects in the Clinic (PENTEC): Radiation Dose-Volume Response for Adverse Effects After Childhood Cancer Therapy and Future Directions. Int J Radiat Oncol Biol Phys, 2024. 119(2): p. 321-337.2. Van Ooteghem, G., et al., Mechanically- assisted and non-invasive ventilation for radiation therapy: A safe technique to regularize and modulate internal tumour motion. Radiother Oncol, 2019. 141: p. 283-291.3. Vander Veken, L., et al., Lung and Liver Stereotactic Body Radiation Therapy During Mechanically Assisted Deep Inspiration Breath-Holds: A Prospective Feasibility Trial. Adv Radiat Oncol, 2024. 9(9): p. 101563. Keywords: Mechanical ventilation, breath-hold, feasibility Digital Poster Highlight 3143 Long-term patient-reported cognitive function in pediatric leukemia patients after stem cell transplantation with total body irradiation conditioning
The patient successfully performed stable and reproducible 20-second breath-holds across all the 10
Made with FlippingBook - Share PDF online